US20060114856A1 - Mobile IP network system and connection switching method - Google Patents
Mobile IP network system and connection switching method Download PDFInfo
- Publication number
- US20060114856A1 US20060114856A1 US11/332,180 US33218006A US2006114856A1 US 20060114856 A1 US20060114856 A1 US 20060114856A1 US 33218006 A US33218006 A US 33218006A US 2006114856 A1 US2006114856 A1 US 2006114856A1
- Authority
- US
- United States
- Prior art keywords
- packet
- mobile station
- node
- base station
- mobile
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000000034 method Methods 0.000 title claims description 34
- 238000004891 communication Methods 0.000 claims abstract description 43
- 230000005540 biological transmission Effects 0.000 claims description 25
- 238000012546 transfer Methods 0.000 claims description 21
- 238000012544 monitoring process Methods 0.000 claims description 16
- 230000006870 function Effects 0.000 description 20
- 238000010276 construction Methods 0.000 description 17
- 238000010586 diagram Methods 0.000 description 15
- 238000012545 processing Methods 0.000 description 11
- 230000004044 response Effects 0.000 description 9
- 230000008569 process Effects 0.000 description 4
- 238000005259 measurement Methods 0.000 description 3
- 238000010295 mobile communication Methods 0.000 description 3
- 230000008859 change Effects 0.000 description 2
- 230000006399 behavior Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000008520 organization Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L69/00—Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass
- H04L69/16—Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
- H04L69/168—Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP] specially adapted for link layer protocols, e.g. asynchronous transfer mode [ATM], synchronous optical network [SONET] or point-to-point protocol [PPP]
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L69/00—Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass
- H04L69/16—Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
- H04L9/40—Network security protocols
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W36/00—Hand-off or reselection arrangements
- H04W36/0005—Control or signalling for completing the hand-off
- H04W36/0011—Control or signalling for completing the hand-off for data sessions of end-to-end connection
- H04W36/0019—Control or signalling for completing the hand-off for data sessions of end-to-end connection adapted for mobile IP [MIP]
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W76/00—Connection management
- H04W76/10—Connection setup
- H04W76/12—Setup of transport tunnels
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W36/00—Hand-off or reselection arrangements
- H04W36/0005—Control or signalling for completing the hand-off
- H04W36/0011—Control or signalling for completing the hand-off for data sessions of end-to-end connection
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W8/00—Network data management
- H04W8/26—Network addressing or numbering for mobility support
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W80/00—Wireless network protocols or protocol adaptations to wireless operation
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W80/00—Wireless network protocols or protocol adaptations to wireless operation
- H04W80/04—Network layer protocols, e.g. mobile IP [Internet Protocol]
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W92/00—Interfaces specially adapted for wireless communication networks
- H04W92/02—Inter-networking arrangements
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W92/00—Interfaces specially adapted for wireless communication networks
- H04W92/04—Interfaces between hierarchically different network devices
- H04W92/12—Interfaces between hierarchically different network devices between access points and access point controllers
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W92/00—Interfaces specially adapted for wireless communication networks
- H04W92/16—Interfaces between hierarchically similar devices
- H04W92/24—Interfaces between hierarchically similar devices between backbone network devices
Definitions
- the present invention relates to a mobile IP network system and a connection switching method. More particularly, the invention relates to a technique of switching a logical connection for IP packet communications between a radio access network and a packet node connected to an IP (Internet Protocol) network in association with movement of a mobile station.
- IP Internet Protocol
- the mobile IP denotes a technique for enabling the communication between a mobile station and a host to be continued without changing an IP address even when the connection position between the mobile station and the IP network changes.
- a node having a home agent function for each of mobile stations is preliminarily determined.
- the home agent function denotes a function of grasping the current position of mobile stations under the control, when an IP packet destined for a mobile station under the control is received, converting the reception packet to an encapsulated packet destined for a packet node connected to a radio access network in which the mobile station is positioned at present, and transmitting the encapsulated packet to the IP network.
- Each of packet nodes for receiving the encapsulated packet via the IP network has a foreign agent function.
- the foreign agent function denotes here a function of decapsulating the reception packet and transmitting the obtained IP packet to a radio access network in which a destination mobile station is positioned.
- an IP packet can be delivered to the mobile station without changing the IP address of a transmission packet.
- a node having the home agent function will be called a home agent node and a node having the foreign agent function will be called a foreign agent node.
- a communication between a mobile station and a host connected to an IP network is realized by switching a logical connection between the mobile station and a foreign agent node by using a position control function peculiar to a mobile communication network and routing an IP packet between the foreign agent node and the host by the mobile IP function.
- the mobile IP is standardized by IETF and is described in, for example, “IP Mobility Support”, C. Perkins, RFC2002, October 1996.
- a mobile IP data communication in IMT-2000 as a third-generation mobile communication network is described in “Wireless IP Network Architecture based on IETF Protocols”, Tom Hiller, 1999 disclosed by TIA as a standardization organization in North America.
- the mobile station notifies the home agent node of a destination packet node and the home agent node registers the destination packet node as a new foreign agent for the mobile station. Consequently, the home agent node can transfer an IP packet destined for the mobile station received after that to the new foreign agent (packet node on the destination side).
- the conventional technique has a problem such that it takes time from the request of the registration procedure to the response. Specifically, when a mobile station moves to a control area of another packet node and is handed over to a radio base station in the control area, until the registration is completed in the home agent node, IP packets destined for the mobile station are transferred from the home agent node to a packet node in the previous control area, so that the IP packets are not transferred to the mobile station.
- the dropped IP packets may be compensated by retransmission of the IP packets from the host in response to a request from the mobile station, when the amount of the dropped IP packets is large, a problem such that the retransmission of the IP packets severely deteriorates the throughput occurs.
- the present invention is characterized in that each of base station controllers in a radio access network selectively establishes a logical connection or a logical link with a plurality of packet nodes each having a foreign agent function.
- a mobile IP network system of the invention comprises: a plurality of radio access networks each connected to a mobile station via a radio link; and an IP network to which a plurality of packet nodes for transferring an IP packet are connected, and is characterized in that a base station controller in each of the radio access networks is connected to the plurality of packet nodes, and each of the base station controllers selects one of the plurality of packet nodes in accordance with a state of each mobile station, and sets a logical connection to be used in IP packet communication of the mobile station.
- the base station controller when a mobile station is moved from a control area of another radio access network to the control area of one of the base station controllers, the base station controller can sets a logical connection for the mobile station with a previous packet node which has communicated with the mobile station in the control area of the another radio access network. That is, according to the invention, when a mobile station is moved from a radio access network to another radio access network, the IP packet communication can be continued without performing a registration procedure for switching a foreign agent node. Thus, the problem of the dropout of IP packets in association with the registration procedure can be solved.
- each of the base station controllers has means for monitoring a transmitting and receiving state of data to and from a mobile station which has moved from the control area of another radio access network, detects that data transmission and reception of the mobile station is stopped, cancels the logical connection between the base station controller and the previous packet node, and sets a new logical connection for the mobile station between the base station controller and a preliminarily designated specific packet node.
- the registration procedure by the home agent node is necessary. According to the invention, however, since the registration procedure is performed during the data transmission and reception of the mobile terminal is stopped, the problem of the dropout does not occur.
- FIG. 1 is a diagram schematically showing the construction of a conventional mobile IP network system.
- FIG. 2 is a diagram specifically showing a radio access network 2 .
- FIG. 3 is a diagram showing schematic constructions of a mobile station 1 , a radio access network 2 , a packet node 3 , and a home agent node 5 in FIG. 1 .
- FIG. 4 is a diagram showing schematic constructions of base stations 6 and base station controllers 7 constructing the radio access network 2 .
- FIG. 5 is a diagram showing a schematic construction of a control unit 31 in the packet node 3 .
- FIG. 6 is a diagram for explaining the flow of communication data between the mobile station 1 and the host 4 in the conventional mobile IP network system.
- FIG. 7 is a diagram showing a registration procedure sequence in the conventional mobile IP network system.
- FIG. 8 is a diagram for explaining a change in a transfer route of an IP packet in the conventional mobile IP network system.
- FIG. 9 is a processing sequence for changing a transfer route of an IP packet in the conventional mobile IP network system.
- FIG. 10 is a diagram showing an example of the construction of a mobile IP network system according to the invention.
- FIGS. 11A, 11B and 11 C are diagrams showing formats of a transmission packet from a host to a mobile station, a transfer packet from a home agent node to a packet node, and a transfer packet from the packet node to a base station controller, respectively.
- FIG. 12 is a diagram showing a processing sequence for changing a transfer route of an IP packet in a mobile IP network system of the invention.
- FIG. 13 is a block diagram showing schematic constructions of a mobile station 1 , a radio access network 2 , a packet node 3 and a home agent node 5 constructing a mobile IP network system of the invention.
- FIG. 14 is a diagram specifically showing the radio access network 2 in the invention.
- FIG. 15 is a diagram showing the construction of a control unit 71 in a radio access network of the invention.
- FIG. 16 is a diagram showing the construction of a link management table 203 - 3 in FIG. 15 .
- FIG. 17 is a flowchart showing an example of processing operations of a logical link changing unit 203 - 2 in FIG. 15 .
- FIG. 18 is a flowchart showing another example of processing operations of the logical link changing unit 203 - 2 in FIG. 15 .
- FIG. 1 shows a general construction of the conventional mobile IP network system.
- the mobile IP network system comprises: a mobile station 1 ; a plurality of radio access networks 2 ( 2 A, 2 B, . . . ); packet nodes 3 ( 3 A, 3 B, . . . ) each for connecting each of the radio access networks to an IP network 102 ; a home agent node 5 of the mobile station 1 ; and a host (or server) for performing communications with the mobile station.
- the mobile station 1 and the radio access network 2 are connected via, for example, a radio link 100 using CDMA.
- the radio access network 2 and the packet node 3 are connected via a dedicated line 101 .
- the host 4 and the home agent node 5 are connected to the IP network 102 , and each of the packet nodes 3 has a foreign agent function in a mobile IP.
- Each of the radio access networks 2 ( 2 A, 2 B, . . . ) comprises, for example as shown in FIG. 2 , one or more base station controllers 7 ( 7 A, 7 B, . . . ) connected to the packet node 3 and one or more radio base stations 6 each connected to any of the base station controllers via a dedicated line 103 .
- the packet node 3 and the base station controllers 7 have the connecting relation of 1 to m, and the base station controller 7 and the base stations 6 have the connecting relation of 1 to n.
- the functions of the base station controller 7 and the base station 6 may be collected in a single device called a radio access point.
- FIG. 3 shows schematic constructions of the mobile station 1 , radio access network 2 , packet node 3 and home agent node 5 .
- the mobile station 1 comprises: a man-machine interface (MMI) 12 including an external device interface function; a radio frequency unit (RF unit) 13 for communicating with the radio access network 2 through a radio channel; and a control unit 11 connected to those elements.
- MMI man-machine interface
- RF unit radio frequency unit
- the radio access network 2 comprises: a radio frequency unit (RF unit) 22 for communicating with the mobile station 1 via a radio channel; a dedicated line interface (dedicated line control unit) 23 for communicating with the packet node 3 ; and a control unit 21 connected to those elements.
- RF unit radio frequency unit
- dedicated line interface dedicated line control unit
- the packet node 3 comprises: one or more dedicated line interfaces 32 for communicating with the radio access network 2 ; an IP network interface 33 for a connection to an IP network; and a control unit 31 connected to those elements.
- the home agent node 5 comprises an IP network interface 52 for a connection to the IP network and a control unit 51 .
- FIG. 4 shows an example of a specific construction of the radio access network 2 .
- the radio access network 2 comprises the one or more base station controllers 7 ( 7 A, 7 B, . . . ) and the plurality of base stations 6 ( 6 A, 6 B, 6 C, . . . ) each connected to any of the base station controllers.
- Each base station 6 comprises an RF unit 62 for communicating with the mobile station 1 via a radio channel; a dedicated line interface (dedicated line control unit) 63 for communicating with the base station controller 7 ; and a control unit 61 connected to those elements.
- RF unit 62 for communicating with the mobile station 1 via a radio channel
- dedicated line interface (dedicated line control unit) 63 for communicating with the base station controller 7
- control unit 61 connected to those elements.
- Each of the base station controllers 7 comprises one or more dedicated interfaces (dedicated line control units) 72 for communicating with the base station 6 ; a dedicated line interface (dedicated line control unit) 73 for communicating with the packet node 3 ; and a control unit 71 connected to those elements.
- the RF unit 22 in the radio access network shown in FIG. 3 corresponds to the RF unit 62 in the base station 6
- the dedicated line interface 23 corresponds to the dedicated line interface 73 in the base station control unit 7
- the control unit 21 corresponds to a combination of the control unit 61 in the base station and the control unit 71 in the base station controller.
- FIG. 5 shows the construction of the control unit 31 in the packet node 3 .
- an OS 202 operates on hardware 201 comprising a CPU and a memory, and AP (application software) 203 which determines the behavior of a packet node operates under the control of the OS 202 .
- AP application software
- FIG. 6 shows the flow of communication data between the mobile station 1 and the host 4 in the conventional mobile IP network system.
- the host 4 generates an IP packet including transmission data to the mobile station 1 and an IP address of the mobile station 1 and transmits the IP packet to the IP network 102 .
- the IP packet is received by the home agent node 5 of the mobile station 1 .
- the home agent node 5 stores the corresponding relation between an IP address of each of mobile stations under the control and an IP address of each of packet nodes connected to the radio access network as a destination.
- the home agent node 5 obtains the IP address of the packet node 3 A to which the reception packet is transferred on the basis of the IP address of the mobile station included in the reception packet from the host 4 , adds (encapsulates) a new header in which the IP address of the packet node 3 A is set as a destination address to the reception packet, and transmits the resultant to the IP network 102 .
- Each of the packet nodes 3 stores the corresponding relation between the IP address of each of the mobile stations connected to the radio access network under the control and an ID of a logical connection (Point to Point Protocol (PPP) connection) between the mobile station and the packet node itself.
- the packet node 3 A removes or decapsulates the IP header from the encapsulated packet received from the home agent node 5 , obtains a PPP connection ID corresponding to the mobile station on the basis of the IP address of the mobile station 1 included in the original IP packet received, adds the PPP connection ID to the original IP packet, and transmits the resultant packet to the radio access network 2 A under the control.
- the packet transmitted from the packet node 3 A is transferred in the radio access network 2 A in accordance with the PPP connection ID and is transmitted from the base station to the mobile station 1 as a destination.
- the transmission data from the mobile station 1 to the host 4 is transmitted to the packet node 3 A via the PPP connection between the mobile station 1 and the packet node 3 A as an IP packet including the IP address of the host 4 as a destination address.
- the IP packet is transferred to the IP network 102 by the packet node 3 A and is received by the host 4 .
- FIG. 7 shows a sequence of a registration procedure in the conventional mobile IP network system.
- a radio link is established between the mobile station 1 and the base station 6 C in the area in which the mobile station 1 is positioned by the base station controller 7 B in the radio access network 2 A (step 401 ).
- a request for starting packet service is sent from the base station controller 7 B in the radio access network 2 A to the packet node 3 A ( 402 ), and a logical connection (PPP connection) is established between the packet node 3 A and the mobile station 1 ( 403 ).
- PPP connection logical connection
- the packet node 3 A After the PPP connection is established, the packet node 3 A notifies the mobile station 1 of the IP address of the packet node itself via the PPP connection (advertisement: 404 ).
- the mobile station 1 which has received the advertisement requests the packet node 3 A for registration ( 405 ), and the packet node 3 A transfers the registration request to the home agent node 5 of the mobile station 1 ( 406 ).
- the home agent node 5 which has received the registration request from the mobile station 1 registers the packet node 3 A as a foreign agent corresponding to the mobile station 1 and then sends a registration response to the packet node 3 A ( 407 ).
- the registration procedure is completed.
- the IP packet transmitted from the host 4 to the mobile station 1 is transferred from the home agent node 5 to the packet node 3 A registered as a foreign agent, so that it can be transferred to the mobile station 1 via the PPP connection established between the packet node 3 A and the mobile station 1 ( 409 ).
- FIG. 8 shows a change in the IP packet transfer route in the conventional IP network system in association with a movement of the mobile station.
- the radio link established between the base station 6 C in the radio access network 2 A and the mobile station 1 and the logical connection (PPP connection) established between the mobile station 1 and the packet node 3 A are released.
- PPP connection logical connection
- a registration procedure is executed in the radio access network 2 B as a destination and the packet node 3 B is registered as a new foreign agent of the mobile station 1 . Consequently, the IP packet transmitted from the host 4 to the mobile station 1 is transferred from the home agent node 5 to the packet node 3 B and is transferred from the packet node 3 B to the mobile station 1 via the PPP connection as shown by arrows with solid lines.
- FIG. 9 shows a processing sequence for changing the IP packet transfer route in the conventional mobile IP network system.
- the mobile station 1 When the mobile station 1 moves toward the control area of the radio access network 2 B while performing communication with the host via the PPP connection with the packet node 3 A ( 409 ), the mobile station 1 compares the reception strength of a control signal received from the base station 6 C in the radio access network 2 A shown in FIG. 8 with that of a control signal received from the base station 6 D in the radio access network 2 B. At a time point the reception strength from the base station 6 D becomes stronger, a request of handover to the base station 6 D is issued ( 501 ).
- the handover request is notified from the base station controller 7 B in the radio access network 2 A to the base station controller 7 C in the radio access network 2 B via a control circuit connecting these base station controllers ( 502 ). If the base station 6 D can accommodate the mobile station 1 , the base station controller 7 C returns a handover response to the base station controller 7 B ( 503 ). When the base station controller 7 B which has received the handover response instructs the handover to the mobile station 1 ( 504 ), the base station 6 D as a destination allocates a radio channel to the mobile station 1 , and a new radio link is established between the mobile station 1 and the radio access network 2 B ( 505 ).
- the base station controller 7 C in the radio access network 2 B establishes the logical connection between the mobile station 1 and the packet node 3 B and requests to start transmission and reception of packets to and from the mobile station 1 ( 506 ). In parallel with this, the base station controller 7 B in the radio access network 2 A closes the logical connection established between the mobile station 1 and the packet node 3 A ( 507 ).
- the packet node 3 B which has received the request from the base station controller 7 C establishes a logical connection (PPP connection) with the mobile station ( 508 ) and notifies the IP address of the packet node to the mobile station 1 (advertisement: 509 ).
- PPP connection logical connection
- the mobile station 1 In response to reception of the advertisement, the mobile station 1 requests a registration of a foreign agent to the packet node 3 B ( 510 ) and the packet node 3 B transfers the registration request to the home agent node 5 ( 511 ). After registering the packet node 3 B as a new foreign agent of the mobile station 1 , the home agent node 5 transmits a registration response to the packet node 3 B ( 512 ). When the registration response is transferred from the packet node 3 B to the mobile station 1 ( 513 ), it is able to perform a packet communication via the PPP connection between the mobile station 1 and the packet node 3 B ( 514 ).
- the registration procedure for switching the foreign agent is executed.
- the home agent node 5 keeps on transferring the IP packets destined to the mobile station 1 to the previous packet node 3 A.
- the mobile station 1 cannot therefore receive the IP packets transmitted from the host during the period T 1 , so that a considerable amount of IP packets are dropped out.
- FIG. 10 shows an example of the construction of a mobile IP network system according to the invention.
- the invention is characterized in that the plurality of packet nodes 3 ( 3 A, 3 B, . . . ) having the foreign agent function which are connected to the IP network 102 and the base station controllers 7 ( 7 A, 7 B, 7 C, . . . ) in the radio access networks 2 are connected via a network 104 such as an ATM network.
- the packet node 3 and the base station controllers 7 have the connecting relation of 1 to m via the dedicated lines 101 , and each of the base station controllers can communicate with the IP network only via a specific packet node coupled via a dedicated line.
- the packet nodes 3 and the base station controllers 7 have the connecting relation of k to m (k, m ⁇ 2) via the network 104 .
- a logical connection can be selectively established between each of the base station controllers 7 and any of the packet nodes 3 .
- the present invention is characterized in that, for example, when the mobile station 1 which is performing the IP packet communication via the packet node 3 A moves from the radio access network 2 A to the radio access network 2 B and is handed over from the base station 6 C to the base station 6 D, the base station controller 7 C in the destination establishes a logical connection with the previous packet node 3 A so that the mobile station 1 can continue the IP packet communication via the packet node 3 A.
- the home agent node 5 has a management table in which the IP address of a packet node in the radio access network in which each of the mobile stations is positioned at present is stored in correspondence with the IP address of a mobile station under the control.
- the home agent node 5 refers to the management table on the basis of the IP address 601 of the destination mobile station included in the reception packet PA and retrieves the IP address of the packet node 3 A to which the reception packet is transferred.
- the home agent node 5 adds an IP header including an IP address 602 of the packet node 3 A as a destination address to the received IP packet PA and transmits the resultant as an encapsulated packet PB shown in FIG. 11B to the IP network 102 .
- the packet node has a management table in which the corresponding relations among the IP address of the mobile station which is performing communication via the PPP connection, the PPP connection ID, and the IP address of the base station controller related to the PPP connection.
- the packet node decapsulates the reception packet PB, refers to the management table on the basis of the destination mobile station IP address 601 in the obtained IP packet PA, and retrieves the corresponding PPP connection ID and the IP address of the base station controller (BSC).
- the packet node 3 A adds a header including a PPP connection ID 603 and an IP address 604 of the base station controller 7 B as a destination address to the reception IP packet PA and transmits the resultant in the form of a packet PC shown in FIG. 11C to the network 104 .
- the network 104 is an ATM network
- the packet PC is converted to a plurality of ATM cells to each of which a cell header including an ID (VPI/VCI) of the logical connection between the packet node 3 A and the base station controller 7 B is added and the resultant is transmitted to the network 104 .
- the base station controller 7 B eliminates the IP address 604 from the reception packet PC and transfers the resultant packet to the base station 6 C specified by the PPP connection ID 603 .
- the base station 6 C transfers the reception packet to the mobile station 1 via a radio link specified by the PPP connection ID 603 .
- the mobile station 1 checks the destination IP address 601 of the reception packet and performs a process of receiving the IP packet destined to itself.
- FIG. 12 shows a processing sequence for changing the transfer route of the IP packet in the mobile IP network system of the invention.
- the corresponding steps are designated by the same reference numerals.
- description of the above sequence will be omitted here but the processing sequence for changing the IP packet transfer route in the invention will be described.
- a handover request is sent from the mobile station 1 to the base station controller 7 B in the radio access network 2 A ( 501 ), and a radio channel of the radio access network 2 B is allocated to the mobile station 1 via handover procedures 502 , 503 and 504 similar to the conventional handover procedures ( 505 ).
- the base station controller 7 B in the radio access network 2 A which has received the handover request ( 501 ) from the mobile station 1 notifies the handover request to the base station controller 7 C in the radio access network 2 B
- the ID of the packet node 3 A to which the mobile station 1 is presently PPP connected is also notified to the base station controller 7 C ( 502 ).
- the base station 6 C itself may send the handover request ( 501 ) with respect to the mobile station 1 to the base station controller 7 B when the base station 6 C detects that the strength of the received radio wave from the mobile station 1 which is performing communications drops below a predetermined level. It is also possible that the mobile station 1 issues a handover request to the base station controller 7 C via the destination base station 6 D and the base station controller 7 C instructs handover to the mobile station 1 . In this case, the base station controller 7 C has to be notified of the ID of the base station controller 7 B, which is being connected from the mobile station 1 , to inquire the base station controller 7 B of the ID of the packet node which is PPP connected to the mobile station 1 .
- the base station controller 7 C connected to the base station 6 D sends a request of the packet transmission and reception to and from the mobile station 1 to the specific packet node 3 B preliminarily designated ( 506 ) and a new logical connection (PPP connection) to communication with the mobile station 1 is established ( 508 ).
- the base station controller 7 C sends the request of packet transmission and reception to and from the mobile station 1 to the previous packet node 3 A to which the mobile station 1 is PPP connected at the time of handover ( 701 ).
- the packet node 3 A changes the destination address 604 to the IP address of the base station controller 7 C as a request source in a state where the PPP connection to the mobile station 1 is maintained, and transfers the IP packet destined to the mobile station 1 to the base station controller 7 C.
- a preset PVC Permanent Virtual Connection
- the base station controller 7 B closes the logical connection for the mobile station 1 between the base station controller 7 B and the packet node 3 A ( 702 ). In this case, since the connecting relation between the mobile station 1 and the packet node 3 A is unchanged, the registration procedure of the foreign agent node is unnecessary and communication interruption time T 2 in the destination radio access network 2 B is extremely short.
- each of the base station controllers monitors a transmitting and receiving state of the IP packet for each mobile station under control, confirms that the transmission and reception of the IP packet to and from the mobile station is ceased, and executes the registration procedure.
- the base station controller 7 C is provided with a data flow monitoring timer for repeating measurement of elapsed time each time the IP packet is transmitted and received to and from the mobile station 1 . When the data flow timer times out, it is determined that the transmission and reception of the IP packet is ceased.
- a request of starting packet service (packet transmission and reception) is sent to a specific packet node (in this example, the packet node 3 B) which is preliminarily designated for each base station controller ( 506 ) and the logical connection related to the mobile station 1 with the packet node 3 A which has been performing communications is closed ( 704 ).
- the logical connection (PPP connection) between the mobile station 1 and the packet node 3 B is established ( 508 ) and a registration is executed by a procedure ( 509 to 513 ) similar to the conventional one.
- the base station controller 7 C requests the specific packet node 3 B to set a temporary logical connection and, when the data flow monitoring timer times out, an advertisement request is issued to the mobile station 1 . It is also possible to restart the data flow monitoring timer by the base station controller 7 C after completion of the registration procedure and, when the timer times out again, a dormant processing ( 705 ) for releasing the radio channel allocated to the mobile station 1 may be executed in order to effectively use the radio channel.
- FIG. 13 shows schematic constructions of the mobile station 1 , radio access network 2 , packet node 3 and home agent node 5 which construct the mobile IP network system of the invention.
- the radio access network 2 and the packet node 3 have interfaces (IP network interfaces: ATM network interfaces) 24 and 34 for connection to the common network 104 in place of the dedicated line interfaces 23 and 32 .
- IP network interfaces ATM network interfaces
- FIG. 14 specifically shows the construction of the radio access network 2 .
- Each of the base station controllers 7 ( 7 A and 7 B) in the radio access network 2 has a line interface (IP network interface: ATM network interface) 74 for connection to the common network 104 in place of the dedicated line interface 73 for communicating with the packet node 3 .
- the common network 104 is an IP network such as an ATM network and includes IP nodes (ATM switches) 8 A, 8 B, 8 C, . . . for accommodating the plurality of base station controllers 7 and the plurality of packet nodes 3 .
- FIG. 15 shows an embodiment of the control unit 71 in the base station controller in each of the radio access networks.
- the control unit 71 in the base station controller comprises: hardware 201 such as a CPU and a memory, a real-time OS 202 , and an application 203 which operates under the control of the OS.
- the application has not only a radio resource management unit 203 - 1 but also, for each of the mobile stations under the control, a data flow monitor 203 - 4 for monitoring the flow of transmission and reception data, a data flow monitoring timer 203 - 5 for measuring time in which the data transmission and reception to and from each of the mobile stations is ceased on the basis of the result of the monitoring of the data flow monitor, a timer information table 203 - 6 for storing data such as a time-out value required by the data flow monitoring timer, a link management table 203 - 3 for memorizing a packet node which is PPP connected at present for each mobile station under the control, and a logical connection changing unit 203 - 2 for controlling the switching of the logical connection (PP connection) on the basis of the link management table.
- the link management table 203 - 3 stores, for example as shown in FIG. 16 , the relations among an ID 301 of a mobile station under the control of the base station controller 7 , an ID 302 of a packet node to which the mobile station is PPP connected at present, and an ID 303 of a preliminarily designated specific packet node.
- an ID 303 of the specific packet node a packet node having the shortest connecting path with the base station controller 7 is registered.
- FIG. 17 shows processes of the logical link changing unit 203 - 2 executed by the control unit 71 in the base station controller 7 when the data flow monitoring timer 203 - 5 times out.
- the logical link changing unit 203 - 2 refers to the link management table 203 - 3 and compares the packet node 302 in connection and the designated packet node 303 , corresponding to the mobile station, thereby determining whether or not the mobile station is PPP connected to the preliminarily designated specific packet node (step 801 ).
- the routine advances to a dormant mode and the radio channel allocated to the mobile station is released ( 802 ).
- the data flow monitoring timer is started again and the process is terminated ( 804 ). If the mobile station is PPP connected to a packet node except for the designated packet node, a request for starting the transmission and reception of packets to and from the mobile station is issued to the designated packet node in order to PPP connect the mobile station to the designated packet node. After the ID of the designated packet node is registered in the packet node in connection field 302 ( 803 ), the data flow monitoring timer is started again and the process is terminated ( 804 ).
- FIG. 18 shows the processing operation of the logical link changing unit 203 - 2 in the base station controller 7 in the radio access network 2 which does not have the dormant processing function.
- the logical link changing unit 203 - 2 waits for a time-out signal from the data flow monitor 203 - 4 ( 901 ).
- a time-out signal is received, that is, it is detected that the data transmission and reception of a certain mobile station is ceased for predetermined time or longer, it is determined, by referring to the link management table 203 - 3 , whether or not the mobile station is PPP connected to the specific packet node preliminarily designated in the self base station controller ( 902 ).
- measurement of the data flow is started again ( 904 ).
- the mobile station is PPP connected to a packet node other than the designated packet node
- a request for starting the transmission and reception of a packet to and from the mobile station is sent to the designated packet node and the ID of the designated packet node is registered in the field 302 of the packet node in connection ( 903 ).
- the measurement of the data flow is started again ( 904 ).
- the invention is characterized in that the plurality of packet nodes 3 connected to the IP network 102 and a plurality of base station controllers 7 in the radio access network 2 are connected to each other via the network 104 , and each of the base station controllers can selectively connect the mobile station handed over from another radio access network to any of the packet nodes.
- the network 104 for connecting the packet node 3 and the base station controller to each other and the IP network 102 to which the home agent node is connected are separate networks.
- the network 104 may be a part of the IP network 102 . That is, the following manner may be also used in which each of the base station controllers 7 is connected to the IP network 102 and, for example, the packet node 3 A transfers an IP packet, which is transferred from the home agent 5 to the packet node 3 A via the IP network 102 , to the base station controller 7 B or 7 C via the IP network 102 .
- a logical connection can be selectively established between each of the base station controllers in the radio access network and an arbitrary packet node having the foreign agent function. Consequently, when a mobile station is handed over from one radio access network to another radio access network, without switching the foreign agent node in the destination radio access network, the mobile station can be logically connected to the previous packet node and the IP packet communication can be continued. The mobile IP packet communication which avoids dropout of packets during execution of the registration for switching the foreign agent node can be therefore performed.
- the registration of the foreign agent node is executed during the period in which the IP packet transmission and reception is ceased, even when the foreign agent node is switched to the optimum packet terminal in association with the movement of the mobile station, dropout of packets during the registration period can be avoided.
Abstract
In a mobile IP network system including a plurality of radio access networks for connecting with mobile stations via radio links and an IP network connected with a plurality of packet nodes for transferring IP packets, each of the radio access networks has at least one base station controller and at least one radio base station connected to the base station controller. Each of the base station controllers in the radio access network is connected to the plurality of packet nodes to each other via a network and selects one of the plurality of packet nodes in accordance with a state of each mobile station to establish a logical connection to be used in IP packet communication of the mobile station.
Description
- The present application is a continuation of application Ser. No. 09/624,072, filed Jul. 24, 2000, the contents of which are incorporated herein by reference.
- The present invention relates to a mobile IP network system and a connection switching method. More particularly, the invention relates to a technique of switching a logical connection for IP packet communications between a radio access network and a packet node connected to an IP (Internet Protocol) network in association with movement of a mobile station.
- In order to enable IP data to be transferred between a mobile station and a host connected to an IP network typified by the Internet, a network system in which a mobile communication network is connected to the IP network via a packet node having a foreign agent function in a mobile IP is being examined.
- The mobile IP denotes a technique for enabling the communication between a mobile station and a host to be continued without changing an IP address even when the connection position between the mobile station and the IP network changes. In the mobile IP, a node having a home agent function for each of mobile stations is preliminarily determined. The home agent function denotes a function of grasping the current position of mobile stations under the control, when an IP packet destined for a mobile station under the control is received, converting the reception packet to an encapsulated packet destined for a packet node connected to a radio access network in which the mobile station is positioned at present, and transmitting the encapsulated packet to the IP network.
- Each of packet nodes for receiving the encapsulated packet via the IP network has a foreign agent function. The foreign agent function denotes here a function of decapsulating the reception packet and transmitting the obtained IP packet to a radio access network in which a destination mobile station is positioned.
- By the home agent function and the foreign agent function, even when a mobile station moves between radio access networks, an IP packet can be delivered to the mobile station without changing the IP address of a transmission packet.
- In the following, a node having the home agent function will be called a home agent node and a node having the foreign agent function will be called a foreign agent node.
- A communication between a mobile station and a host connected to an IP network is realized by switching a logical connection between the mobile station and a foreign agent node by using a position control function peculiar to a mobile communication network and routing an IP packet between the foreign agent node and the host by the mobile IP function.
- The mobile IP is standardized by IETF and is described in, for example, “IP Mobility Support”, C. Perkins, RFC2002, October 1996. A mobile IP data communication in IMT-2000 as a third-generation mobile communication network is described in “Wireless IP Network Architecture based on IETF Protocols”, Tom Hiller, 1999 disclosed by TIA as a standardization organization in North America.
- In the mobile IP, when a mobile station is moved from a control area of a packet node (foreign agent node) to a control area of another packet node, a registration procedure for switching the foreign agent node is necessary in the home agent node.
- The mobile station notifies the home agent node of a destination packet node and the home agent node registers the destination packet node as a new foreign agent for the mobile station. Consequently, the home agent node can transfer an IP packet destined for the mobile station received after that to the new foreign agent (packet node on the destination side).
- The conventional technique has a problem such that it takes time from the request of the registration procedure to the response. Specifically, when a mobile station moves to a control area of another packet node and is handed over to a radio base station in the control area, until the registration is completed in the home agent node, IP packets destined for the mobile station are transferred from the home agent node to a packet node in the previous control area, so that the IP packets are not transferred to the mobile station. Although the dropped IP packets may be compensated by retransmission of the IP packets from the host in response to a request from the mobile station, when the amount of the dropped IP packets is large, a problem such that the retransmission of the IP packets severely deteriorates the throughput occurs.
- It is an object of the invention to provide a mobile IP network system and a connection switching method in which dropout of an IP packet which occurs during a registration procedure of a destination packet node is prevented.
- In order to achieve the object, the present invention is characterized in that each of base station controllers in a radio access network selectively establishes a logical connection or a logical link with a plurality of packet nodes each having a foreign agent function.
- More specifically, a mobile IP network system of the invention comprises: a plurality of radio access networks each connected to a mobile station via a radio link; and an IP network to which a plurality of packet nodes for transferring an IP packet are connected, and is characterized in that a base station controller in each of the radio access networks is connected to the plurality of packet nodes, and each of the base station controllers selects one of the plurality of packet nodes in accordance with a state of each mobile station, and sets a logical connection to be used in IP packet communication of the mobile station.
- In the network system according to the invention, when a mobile station is moved from a control area of another radio access network to the control area of one of the base station controllers, the base station controller can sets a logical connection for the mobile station with a previous packet node which has communicated with the mobile station in the control area of the another radio access network. That is, according to the invention, when a mobile station is moved from a radio access network to another radio access network, the IP packet communication can be continued without performing a registration procedure for switching a foreign agent node. Thus, the problem of the dropout of IP packets in association with the registration procedure can be solved.
- Another characteristic of a mobile IP network system according to the invention is that each of the base station controllers has means for monitoring a transmitting and receiving state of data to and from a mobile station which has moved from the control area of another radio access network, detects that data transmission and reception of the mobile station is stopped, cancels the logical connection between the base station controller and the previous packet node, and sets a new logical connection for the mobile station between the base station controller and a preliminarily designated specific packet node.
- When the packet node to be connected to the base station controller via the logical connection is switched, the registration procedure by the home agent node is necessary. According to the invention, however, since the registration procedure is performed during the data transmission and reception of the mobile terminal is stopped, the problem of the dropout does not occur.
- The foregoing and other objects, advantages, manner of the operation and novel features of the present invention will be understood from the following detailed description when read in conjunction with the accompanying drawings.
-
FIG. 1 is a diagram schematically showing the construction of a conventional mobile IP network system. -
FIG. 2 is a diagram specifically showing aradio access network 2. -
FIG. 3 is a diagram showing schematic constructions of amobile station 1, aradio access network 2, apacket node 3, and ahome agent node 5 inFIG. 1 . -
FIG. 4 is a diagram showing schematic constructions of base stations 6 and base station controllers 7 constructing theradio access network 2. -
FIG. 5 is a diagram showing a schematic construction of acontrol unit 31 in thepacket node 3. -
FIG. 6 is a diagram for explaining the flow of communication data between themobile station 1 and thehost 4 in the conventional mobile IP network system. -
FIG. 7 is a diagram showing a registration procedure sequence in the conventional mobile IP network system. -
FIG. 8 is a diagram for explaining a change in a transfer route of an IP packet in the conventional mobile IP network system. -
FIG. 9 is a processing sequence for changing a transfer route of an IP packet in the conventional mobile IP network system. -
FIG. 10 is a diagram showing an example of the construction of a mobile IP network system according to the invention. -
FIGS. 11A, 11B and 11C are diagrams showing formats of a transmission packet from a host to a mobile station, a transfer packet from a home agent node to a packet node, and a transfer packet from the packet node to a base station controller, respectively. -
FIG. 12 is a diagram showing a processing sequence for changing a transfer route of an IP packet in a mobile IP network system of the invention. -
FIG. 13 is a block diagram showing schematic constructions of amobile station 1, aradio access network 2, apacket node 3 and ahome agent node 5 constructing a mobile IP network system of the invention. -
FIG. 14 is a diagram specifically showing theradio access network 2 in the invention. -
FIG. 15 is a diagram showing the construction of acontrol unit 71 in a radio access network of the invention. -
FIG. 16 is a diagram showing the construction of a link management table 203-3 inFIG. 15 . -
FIG. 17 is a flowchart showing an example of processing operations of a logical link changing unit 203-2 inFIG. 15 . -
FIG. 18 is a flowchart showing another example of processing operations of the logical link changing unit 203-2 inFIG. 15 . - First, for easier understanding of the present invention, a conventional mobile IP network system will be described with reference to FIGS. 1 to 9.
-
FIG. 1 shows a general construction of the conventional mobile IP network system. - The mobile IP network system comprises: a
mobile station 1; a plurality of radio access networks 2 (2A, 2B, . . . ); packet nodes 3 (3A, 3B, . . . ) each for connecting each of the radio access networks to anIP network 102; ahome agent node 5 of themobile station 1; and a host (or server) for performing communications with the mobile station. Themobile station 1 and theradio access network 2 are connected via, for example, aradio link 100 using CDMA. Theradio access network 2 and thepacket node 3 are connected via adedicated line 101. Thehost 4 and thehome agent node 5 are connected to theIP network 102, and each of thepacket nodes 3 has a foreign agent function in a mobile IP. - Each of the radio access networks 2 (2A, 2B, . . . ) comprises, for example as shown in
FIG. 2 , one or more base station controllers 7 (7A, 7B, . . . ) connected to thepacket node 3 and one or more radio base stations 6 each connected to any of the base station controllers via adedicated line 103. Thepacket node 3 and the base station controllers 7 have the connecting relation of 1 to m, and the base station controller 7 and the base stations 6 have the connecting relation of 1 to n. The functions of the base station controller 7 and the base station 6 may be collected in a single device called a radio access point. -
FIG. 3 shows schematic constructions of themobile station 1,radio access network 2,packet node 3 andhome agent node 5. - The
mobile station 1 comprises: a man-machine interface (MMI) 12 including an external device interface function; a radio frequency unit (RF unit) 13 for communicating with theradio access network 2 through a radio channel; and a control unit 11 connected to those elements. - The
radio access network 2 comprises: a radio frequency unit (RF unit) 22 for communicating with themobile station 1 via a radio channel; a dedicated line interface (dedicated line control unit) 23 for communicating with thepacket node 3; and acontrol unit 21 connected to those elements. - The
packet node 3 comprises: one or more dedicated line interfaces 32 for communicating with theradio access network 2; anIP network interface 33 for a connection to an IP network; and acontrol unit 31 connected to those elements. - The
home agent node 5 comprises anIP network interface 52 for a connection to the IP network and acontrol unit 51. -
FIG. 4 shows an example of a specific construction of theradio access network 2. - The
radio access network 2 comprises the one or more base station controllers 7 (7A, 7B, . . . ) and the plurality of base stations 6 (6A, 6B, 6C, . . . ) each connected to any of the base station controllers. - Each base station 6 comprises an
RF unit 62 for communicating with themobile station 1 via a radio channel; a dedicated line interface (dedicated line control unit) 63 for communicating with the base station controller 7; and acontrol unit 61 connected to those elements. - Each of the base station controllers 7 comprises one or more dedicated interfaces (dedicated line control units) 72 for communicating with the base station 6; a dedicated line interface (dedicated line control unit) 73 for communicating with the
packet node 3; and acontrol unit 71 connected to those elements. - The
RF unit 22 in the radio access network shown inFIG. 3 corresponds to theRF unit 62 in the base station 6, thededicated line interface 23 corresponds to thededicated line interface 73 in the base station control unit 7, and thecontrol unit 21 corresponds to a combination of thecontrol unit 61 in the base station and thecontrol unit 71 in the base station controller. -
FIG. 5 shows the construction of thecontrol unit 31 in thepacket node 3. - In the
control unit 31, anOS 202 operates onhardware 201 comprising a CPU and a memory, and AP (application software) 203 which determines the behavior of a packet node operates under the control of theOS 202. Each of the control units in themobile station 1, base station 6, base station controller 7 andhome agent node 5 has basically the construction similar to that of thecontrol unit 31. -
FIG. 6 shows the flow of communication data between themobile station 1 and thehost 4 in the conventional mobile IP network system. - The
host 4 generates an IP packet including transmission data to themobile station 1 and an IP address of themobile station 1 and transmits the IP packet to theIP network 102. The IP packet is received by thehome agent node 5 of themobile station 1. - The
home agent node 5 stores the corresponding relation between an IP address of each of mobile stations under the control and an IP address of each of packet nodes connected to the radio access network as a destination. Thehome agent node 5 obtains the IP address of thepacket node 3A to which the reception packet is transferred on the basis of the IP address of the mobile station included in the reception packet from thehost 4, adds (encapsulates) a new header in which the IP address of thepacket node 3A is set as a destination address to the reception packet, and transmits the resultant to theIP network 102. - Each of the
packet nodes 3 stores the corresponding relation between the IP address of each of the mobile stations connected to the radio access network under the control and an ID of a logical connection (Point to Point Protocol (PPP) connection) between the mobile station and the packet node itself. Thepacket node 3A removes or decapsulates the IP header from the encapsulated packet received from thehome agent node 5, obtains a PPP connection ID corresponding to the mobile station on the basis of the IP address of themobile station 1 included in the original IP packet received, adds the PPP connection ID to the original IP packet, and transmits the resultant packet to theradio access network 2A under the control. The packet transmitted from thepacket node 3A is transferred in theradio access network 2A in accordance with the PPP connection ID and is transmitted from the base station to themobile station 1 as a destination. - The transmission data from the
mobile station 1 to thehost 4 is transmitted to thepacket node 3A via the PPP connection between themobile station 1 and thepacket node 3A as an IP packet including the IP address of thehost 4 as a destination address. The IP packet is transferred to theIP network 102 by thepacket node 3A and is received by thehost 4. -
FIG. 7 shows a sequence of a registration procedure in the conventional mobile IP network system. - In order to realize an IP packet transfer by the above-described mobile IP, it is necessary to register in the home agent node a packet node, between which and the mobile station the logical connection (PPP connection) is established, as a foreign agent node.
- When a radio link is established between the
mobile station 1 and thebase station 6C in the area in which themobile station 1 is positioned by thebase station controller 7B in theradio access network 2A (step 401), a request for starting packet service (transmission and reception of packets) is sent from thebase station controller 7B in theradio access network 2A to thepacket node 3A (402), and a logical connection (PPP connection) is established between thepacket node 3A and the mobile station 1 (403). - After the PPP connection is established, the
packet node 3A notifies themobile station 1 of the IP address of the packet node itself via the PPP connection (advertisement:404). Themobile station 1 which has received the advertisement requests thepacket node 3A for registration (405), and thepacket node 3A transfers the registration request to thehome agent node 5 of the mobile station 1 (406). Thehome agent node 5 which has received the registration request from themobile station 1 registers thepacket node 3A as a foreign agent corresponding to themobile station 1 and then sends a registration response to thepacket node 3A (407). - When the
packet node 3A transfers the registration response to the mobile station 1 (408), the registration procedure is completed. By the procedure, the IP packet transmitted from thehost 4 to themobile station 1 is transferred from thehome agent node 5 to thepacket node 3A registered as a foreign agent, so that it can be transferred to themobile station 1 via the PPP connection established between thepacket node 3A and the mobile station 1 (409). -
FIG. 8 shows a change in the IP packet transfer route in the conventional IP network system in association with a movement of the mobile station. - For example, when the
mobile station 1 moves from theradio access network 2A as a control area of thepacket node 3A to theradio access network 2B as a control area of thepacket node 3B, as a result of hand-over between the base stations, the radio link established between thebase station 6C in theradio access network 2A and themobile station 1 and the logical connection (PPP connection) established between themobile station 1 and thepacket node 3A are released. In stead, a radio link between thebase station 6D in theradio access network 2B and themobile station 1 and a logical connection (PPP connection) between themobile station 1 and thepacket node 3B are established. - A registration procedure is executed in the
radio access network 2B as a destination and thepacket node 3B is registered as a new foreign agent of themobile station 1. Consequently, the IP packet transmitted from thehost 4 to themobile station 1 is transferred from thehome agent node 5 to thepacket node 3B and is transferred from thepacket node 3B to themobile station 1 via the PPP connection as shown by arrows with solid lines. -
FIG. 9 shows a processing sequence for changing the IP packet transfer route in the conventional mobile IP network system. - When the
mobile station 1 moves toward the control area of theradio access network 2B while performing communication with the host via the PPP connection with thepacket node 3A (409), themobile station 1 compares the reception strength of a control signal received from thebase station 6C in theradio access network 2A shown inFIG. 8 with that of a control signal received from thebase station 6D in theradio access network 2B. At a time point the reception strength from thebase station 6D becomes stronger, a request of handover to thebase station 6D is issued (501). - The handover request is notified from the
base station controller 7B in theradio access network 2A to thebase station controller 7C in theradio access network 2B via a control circuit connecting these base station controllers (502). If thebase station 6D can accommodate themobile station 1, thebase station controller 7C returns a handover response to thebase station controller 7B (503). When thebase station controller 7B which has received the handover response instructs the handover to the mobile station 1 (504), thebase station 6D as a destination allocates a radio channel to themobile station 1, and a new radio link is established between themobile station 1 and theradio access network 2B (505). - The
base station controller 7C in theradio access network 2B establishes the logical connection between themobile station 1 and thepacket node 3B and requests to start transmission and reception of packets to and from the mobile station 1 (506). In parallel with this, thebase station controller 7B in theradio access network 2A closes the logical connection established between themobile station 1 and thepacket node 3A (507). Thepacket node 3B which has received the request from thebase station controller 7C establishes a logical connection (PPP connection) with the mobile station (508) and notifies the IP address of the packet node to the mobile station 1 (advertisement: 509). - In response to reception of the advertisement, the
mobile station 1 requests a registration of a foreign agent to thepacket node 3B (510) and thepacket node 3B transfers the registration request to the home agent node 5 (511). After registering thepacket node 3B as a new foreign agent of themobile station 1, thehome agent node 5 transmits a registration response to thepacket node 3B (512). When the registration response is transferred from thepacket node 3B to the mobile station 1 (513), it is able to perform a packet communication via the PPP connection between themobile station 1 and thepacket node 3B (514). - As described above, in the conventional mobile IP network system, when a mobile station moves to the control area of another radio access network, in association with a handover of the mobile station between the base stations, the registration procedure for switching the foreign agent is executed. In this case, during a period (T1) since the mobile station is handed over to the destination radio access network until switching of the lo foreign agent is completed, the
home agent node 5 keeps on transferring the IP packets destined to themobile station 1 to theprevious packet node 3A. Themobile station 1 cannot therefore receive the IP packets transmitted from the host during the period T1, so that a considerable amount of IP packets are dropped out. - With reference to FIGS. 10 to 18, the construction of the mobile IP network system according to the invention and the method of switching the connection will be described.
-
FIG. 10 shows an example of the construction of a mobile IP network system according to the invention. - The invention is characterized in that the plurality of packet nodes 3 (3A, 3B, . . . ) having the foreign agent function which are connected to the
IP network 102 and the base station controllers 7 (7A, 7B, 7C, . . . ) in theradio access networks 2 are connected via anetwork 104 such as an ATM network. - In the conventional mobile IP network system, the
packet node 3 and the base station controllers 7 have the connecting relation of 1 to m via thededicated lines 101, and each of the base station controllers can communicate with the IP network only via a specific packet node coupled via a dedicated line. On the contrary, in the mobile IP network system of the invention, thepacket nodes 3 and the base station controllers 7 have the connecting relation of k to m (k, m≧2) via thenetwork 104. A logical connection can be selectively established between each of the base station controllers 7 and any of thepacket nodes 3. - The present invention is characterized in that, for example, when the
mobile station 1 which is performing the IP packet communication via thepacket node 3A moves from theradio access network 2A to theradio access network 2B and is handed over from thebase station 6C to thebase station 6D, thebase station controller 7C in the destination establishes a logical connection with theprevious packet node 3A so that themobile station 1 can continue the IP packet communication via thepacket node 3A. - In the mobile IP network system, for example, as shown in
FIG. 11A , thehost 4 generates an IP packet PA in which an IP header including anIP address 601 of a destination mobile station is added totransmission data 600 destined for themobile station 1 and transmits the IP packet PA to thehome agent node 5 of the destination mobile station. A packet is transferred from thehost 4 to thehome agent node 5 in the form of, for example, an encapsulated packet obtained by adding the IP address of the home agent node as a destination IP address to the IP packet PA. - The
home agent node 5 has a management table in which the IP address of a packet node in the radio access network in which each of the mobile stations is positioned at present is stored in correspondence with the IP address of a mobile station under the control. When a packet from thehost 4 is received, thehome agent node 5 refers to the management table on the basis of theIP address 601 of the destination mobile station included in the reception packet PA and retrieves the IP address of thepacket node 3A to which the reception packet is transferred. Thehome agent node 5 adds an IP header including anIP address 602 of thepacket node 3A as a destination address to the received IP packet PA and transmits the resultant as an encapsulated packet PB shown inFIG. 11B to theIP network 102. - The packet node has a management table in which the corresponding relations among the IP address of the mobile station which is performing communication via the PPP connection, the PPP connection ID, and the IP address of the base station controller related to the PPP connection. When a packet is received from the
home agent node 5, the packet node decapsulates the reception packet PB, refers to the management table on the basis of the destination mobilestation IP address 601 in the obtained IP packet PA, and retrieves the corresponding PPP connection ID and the IP address of the base station controller (BSC). Thepacket node 3A adds a header including aPPP connection ID 603 and anIP address 604 of thebase station controller 7B as a destination address to the reception IP packet PA and transmits the resultant in the form of a packet PC shown inFIG. 11C to thenetwork 104. When thenetwork 104 is an ATM network, the packet PC is converted to a plurality of ATM cells to each of which a cell header including an ID (VPI/VCI) of the logical connection between thepacket node 3A and thebase station controller 7B is added and the resultant is transmitted to thenetwork 104. - The
base station controller 7B eliminates theIP address 604 from the reception packet PC and transfers the resultant packet to thebase station 6C specified by thePPP connection ID 603. Thebase station 6C transfers the reception packet to themobile station 1 via a radio link specified by thePPP connection ID 603. Themobile station 1 checks thedestination IP address 601 of the reception packet and performs a process of receiving the IP packet destined to itself. -
FIG. 12 shows a processing sequence for changing the transfer route of the IP packet in the mobile IP network system of the invention. InFIG. 12 , in order to make comparison with the conventional processing sequence described inFIG. 9 easier, the corresponding steps are designated by the same reference numerals. In the following, on the precondition that the mobile IP network system ofFIG. 10 is used, description of the above sequence will be omitted here but the processing sequence for changing the IP packet transfer route in the invention will be described. - When the
mobile station 1 which is PPP connected to thepacket node 3A is moved to the control area of theradio access network 2B, a handover request is sent from themobile station 1 to thebase station controller 7B in theradio access network 2A (501), and a radio channel of theradio access network 2B is allocated to themobile station 1 viahandover procedures - In the present invention, when the
base station controller 7B in theradio access network 2A which has received the handover request (501) from themobile station 1 notifies the handover request to thebase station controller 7C in theradio access network 2B, the ID of thepacket node 3A to which themobile station 1 is presently PPP connected is also notified to thebase station controller 7C (502). - The
base station 6C itself may send the handover request (501) with respect to themobile station 1 to thebase station controller 7B when thebase station 6C detects that the strength of the received radio wave from themobile station 1 which is performing communications drops below a predetermined level. It is also possible that themobile station 1 issues a handover request to thebase station controller 7C via thedestination base station 6D and thebase station controller 7C instructs handover to themobile station 1. In this case, thebase station controller 7C has to be notified of the ID of thebase station controller 7B, which is being connected from themobile station 1, to inquire thebase station controller 7B of the ID of the packet node which is PPP connected to themobile station 1. - When a radio link is established between the
mobile station 1 and thedestination base station 6D (505), in the conventional system, thebase station controller 7C connected to thebase station 6D sends a request of the packet transmission and reception to and from themobile station 1 to thespecific packet node 3B preliminarily designated (506) and a new logical connection (PPP connection) to communication with themobile station 1 is established (508). In contrast, in the invention, thebase station controller 7C sends the request of packet transmission and reception to and from themobile station 1 to theprevious packet node 3A to which themobile station 1 is PPP connected at the time of handover (701). Thepacket node 3A changes thedestination address 604 to the IP address of thebase station controller 7C as a request source in a state where the PPP connection to themobile station 1 is maintained, and transfers the IP packet destined to themobile station 1 to thebase station controller 7C. When an ATM network is used as thenetwork 104, a preset PVC (Permanent Virtual Connection) can be used for the packet communication between the base station controller and the packet node. - In parallel with the operation of the
base station controller 7C, thebase station controller 7B closes the logical connection for themobile station 1 between thebase station controller 7B and thepacket node 3A (702). In this case, since the connecting relation between themobile station 1 and thepacket node 3A is unchanged, the registration procedure of the foreign agent node is unnecessary and communication interruption time T2 in the destinationradio access network 2B is extremely short. - In the invention, each of the base station controllers monitors a transmitting and receiving state of the IP packet for each mobile station under control, confirms that the transmission and reception of the IP packet to and from the mobile station is ceased, and executes the registration procedure. For example, the
base station controller 7C is provided with a data flow monitoring timer for repeating measurement of elapsed time each time the IP packet is transmitted and received to and from themobile station 1. When the data flow timer times out, it is determined that the transmission and reception of the IP packet is ceased. A request of starting packet service (packet transmission and reception) is sent to a specific packet node (in this example, thepacket node 3B) which is preliminarily designated for each base station controller (506) and the logical connection related to themobile station 1 with thepacket node 3A which has been performing communications is closed (704). By the operation, the logical connection (PPP connection) between themobile station 1 and thepacket node 3B is established (508) and a registration is executed by a procedure (509 to 513) similar to the conventional one. - In order to shorten the time required for the registration, for example, it is also possible that, at the time point a handover request is received (502), the
base station controller 7C requests thespecific packet node 3B to set a temporary logical connection and, when the data flow monitoring timer times out, an advertisement request is issued to themobile station 1. It is also possible to restart the data flow monitoring timer by thebase station controller 7C after completion of the registration procedure and, when the timer times out again, a dormant processing (705) for releasing the radio channel allocated to themobile station 1 may be executed in order to effectively use the radio channel. -
FIG. 13 shows schematic constructions of themobile station 1,radio access network 2,packet node 3 andhome agent node 5 which construct the mobile IP network system of the invention. - The difference from the conventional system shown in
FIG. 3 is that theradio access network 2 and thepacket node 3 have interfaces (IP network interfaces: ATM network interfaces) 24 and 34 for connection to thecommon network 104 in place of the dedicated line interfaces 23 and 32. -
FIG. 14 specifically shows the construction of theradio access network 2. - Each of the base station controllers 7 (7A and 7B) in the
radio access network 2 has a line interface (IP network interface: ATM network interface) 74 for connection to thecommon network 104 in place of thededicated line interface 73 for communicating with thepacket node 3. Thecommon network 104 is an IP network such as an ATM network and includes IP nodes (ATM switches) 8A, 8B, 8C, . . . for accommodating the plurality of base station controllers 7 and the plurality ofpacket nodes 3. -
FIG. 15 shows an embodiment of thecontrol unit 71 in the base station controller in each of the radio access networks. - The
control unit 71 in the base station controller comprises:hardware 201 such as a CPU and a memory, a real-time OS 202, and anapplication 203 which operates under the control of the OS. The application has not only a radio resource management unit 203-1 but also, for each of the mobile stations under the control, a data flow monitor 203-4 for monitoring the flow of transmission and reception data, a data flow monitoring timer 203-5 for measuring time in which the data transmission and reception to and from each of the mobile stations is ceased on the basis of the result of the monitoring of the data flow monitor, a timer information table 203-6 for storing data such as a time-out value required by the data flow monitoring timer, a link management table 203-3 for memorizing a packet node which is PPP connected at present for each mobile station under the control, and a logical connection changing unit 203-2 for controlling the switching of the logical connection (PPP connection) on the basis of the link management table. - The link management table 203-3 stores, for example as shown in
FIG. 16 , the relations among anID 301 of a mobile station under the control of the base station controller 7, anID 302 of a packet node to which the mobile station is PPP connected at present, and anID 303 of a preliminarily designated specific packet node. As theID 303 of the specific packet node, a packet node having the shortest connecting path with the base station controller 7 is registered. -
FIG. 17 shows processes of the logical link changing unit 203-2 executed by thecontrol unit 71 in the base station controller 7 when the data flow monitoring timer 203-5 times out. - When the data transmission and reception of a certain mobile station is stopped for predetermined time or longer and the data flow monitoring timer 203-5 times out, the logical link changing unit 203-2 refers to the link management table 203-3 and compares the
packet node 302 in connection and the designatedpacket node 303, corresponding to the mobile station, thereby determining whether or not the mobile station is PPP connected to the preliminarily designated specific packet node (step 801). - In the case where the mobile station is PPP connected to the preliminarily designated packet node, the routine advances to a dormant mode and the radio channel allocated to the mobile station is released (802). The data flow monitoring timer is started again and the process is terminated (804). If the mobile station is PPP connected to a packet node except for the designated packet node, a request for starting the transmission and reception of packets to and from the mobile station is issued to the designated packet node in order to PPP connect the mobile station to the designated packet node. After the ID of the designated packet node is registered in the packet node in connection field 302 (803), the data flow monitoring timer is started again and the process is terminated (804).
-
FIG. 18 shows the processing operation of the logical link changing unit 203-2 in the base station controller 7 in theradio access network 2 which does not have the dormant processing function. - The logical link changing unit 203-2 waits for a time-out signal from the data flow monitor 203-4 (901). When the time-out signal is received, that is, it is detected that the data transmission and reception of a certain mobile station is ceased for predetermined time or longer, it is determined, by referring to the link management table 203-3, whether or not the mobile station is PPP connected to the specific packet node preliminarily designated in the self base station controller (902).
- When the mobile station is PPP connected to the designated packet node, measurement of the data flow is started again (904). When the mobile station is PPP connected to a packet node other than the designated packet node, in order to PPP connect the mobile station to the designated packet node, a request for starting the transmission and reception of a packet to and from the mobile station is sent to the designated packet node and the ID of the designated packet node is registered in the
field 302 of the packet node in connection (903). After that, the measurement of the data flow is started again (904). - As obviously understood from the embodiment, the invention is characterized in that the plurality of
packet nodes 3 connected to theIP network 102 and a plurality of base station controllers 7 in theradio access network 2 are connected to each other via thenetwork 104, and each of the base station controllers can selectively connect the mobile station handed over from another radio access network to any of the packet nodes. - In the embodiment shown in
FIG. 10 , thenetwork 104 for connecting thepacket node 3 and the base station controller to each other and theIP network 102 to which the home agent node is connected are separate networks. In order to achieve the object of the invention, however, thenetwork 104 may be a part of theIP network 102. That is, the following manner may be also used in which each of the base station controllers 7 is connected to theIP network 102 and, for example, thepacket node 3A transfers an IP packet, which is transferred from thehome agent 5 to thepacket node 3A via theIP network 102, to thebase station controller IP network 102. - As obviously understood from the foregoing embodiment, according to the invention, a logical connection can be selectively established between each of the base station controllers in the radio access network and an arbitrary packet node having the foreign agent function. Consequently, when a mobile station is handed over from one radio access network to another radio access network, without switching the foreign agent node in the destination radio access network, the mobile station can be logically connected to the previous packet node and the IP packet communication can be continued. The mobile IP packet communication which avoids dropout of packets during execution of the registration for switching the foreign agent node can be therefore performed.
- According to the invention, since the registration of the foreign agent node is executed during the period in which the IP packet transmission and reception is ceased, even when the foreign agent node is switched to the optimum packet terminal in association with the movement of the mobile station, dropout of packets during the registration period can be avoided.
Claims (10)
1. A mobile IP network system comprising:
a plurality of radio access networks each connected to mobile stations via radio links; and
an IP network to which a home agent node and a plurality of packet nodes each for transferring IP packets destined for one of mobile stations and received from the home agent node to one of said radio access networks are connected,
wherein each of the radio access networks has at least one base station controller and at least one radio base station which is connected to the base station controller to perform radio communications with a plurality of mobile stations, and
wherein each of the base station controllers is connected to the plurality of packet nodes through a network, receives an identifier of the previous packet node when one of the mobile stations moved into a control area of the base station controller from a control area of the another base station controller belonging to another radio access network, and selects either the previous packet node which is communicating IP packets for the moved mobile station with said home agent node or a preliminarily designated specific packet node in accordance with a communication state of the mobile station, thereby to selectively carry out IP packet communication for the moved mobile station between the base station controller and the previous packet node or IP packet communication between the base station controller and the specific packet node, after performing a registration procedure between the moved mobile station and said home agent node, depending on the communication state of the mobile station.
2. The mobile LP network system according to claim 1 , wherein each of said base station controllers selects, with respect to the mobile station moved from the control area of said another base station controller to the control area of the base station controller, said previous packet node when the moved mobile station is in a state of communicating IP packets with the previous packet node and requests the previous packet node to communicate IP packets for the moved mobile station with the base station controller.
3. The mobile IP network system according to claim 2 , wherein each of said base station controllers has means for monitoring communication packets of the mobile station which has moved from the control area of said another base station controller, thereby to close the communication between the base station controller and the previous packet node and begin the communication between the base station controller and the specific packet node, upon detecting the data transmission and reception of the moved mobile station is ceased.
4. The mobile IP network system according to claim 1 , wherein said specific packet node has means for notifying to a home agent node of the moved mobile station which is connected to the IP network that the mobile station is in a control area of the specific packet node after setting of beginning the communication between the base station controller and the specific packet node so that the home agent node having received the notification transfers IP packets, which are destined for the moved mobile station and received thereafter from the IP network, to the specific packet node.
5. The mobile IP network system according to claim 1 , wherein each of said packet nodes has a foreign agent function for transferring an IP packet received from the home agent node connected to the IP network to any of the base station controllers.
6. A method of switching a connection for communication between a mobile station connected to any of a plurality of radio access networks via a radio link and a plurality of packet nodes connected to an IP network, comprising:
a step of connecting between a mobile station connected to a first radio access network and a first packet node which is preliminarily related with the first radio access network;
a step of transferring, by said first packet node, IP packets for the mobile station which are received from a home agent node of the mobile station, to the first radio access network using an identifier of the first logical connection;
a step of connecting the mobile station to a second radio access network adjacent to the first radio access network when the mobile station moves into an area of the second radio access network; and
a step of requesting from the second radio access network to the first packet node to communicate IP packets for the mobile station with the second radio access network while the mobile station connected to the first packet node,
wherein IP packets are communicated between the mobile station and the first packet node without performing a registration procedure between the mobile station and said home agent node until communication of IP packets for the mobile station is ceased.
7. The switching method according to claim 6 , further comprising:
a step of closing, upon detecting that data transmission and reception ceased, the connection between the mobile node and the first packet node and beginning the connection between the mobile node and the second packet, said second packet node being preliminarily related with the second radio access network.
8. A base station controller for a radio access network for transmitting and receiving an IP packet to and from a packet node which is connected to an IP network and has a foreign agent function for transferring IP packets from a home agent node to mobile stations, comprising:
a first communication interface for connection to a radio base station, a second communication interface for communication with a plurality of packet nodes connected to the IP network, and a control unit connected to the first and second communication interfaces,
wherein the control unit selectively begins an IP packet communication between the base station and the packet node or to transfer IP packets for the mobile station to the mobile station connected to another radio access network, via the second interface;
wherein said control unit has means for selecting, when the mobile station has moved into the control area of the base station controller from said another radio access network, a first packet node which is communicating with the mobile station in the another radio access network, to request the first packet node to transfer IP packets for the mobile station to the base station controller;
means for monitoring communication packets for the mobile station which is communicating with said first packet node; and
means for switching a first connection between the mobile station and the first packet node to a second connection between the mobile station and a second packet node preliminarily related to the base station controller when it is detected by the monitoring means that the transmission of communication packets for the mobile station is stopped,
wherein said connection is established after performing a registration procedure between the moved mobile station and said home agent node.
9. The base station controller according to claim 8 , wherein said control unit has means for notifying the base station controller in adjacent one of the other radio access networks of identification information of a previous packet node which has been communicating with the mobile station when the mobile station moved out from the control area of the base station controller to a control area of the adjacent radio access network.
10. The base station controller according to claim 8 , wherein said second communication interface is connected to a communication network for connecting the plurality of packet nodes, and said switching means closes the first connection by requesting said first packet node to communicate IP packets for the moved mobile station with the base station controller and establishes said second connection by requesting said second packet node to communicate IP packets for the moved mobile station with the base station controller, when said monitoring means detects that the transmission of communication packets has stopped.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/332,180 US20060114856A1 (en) | 1999-07-22 | 2006-01-17 | Mobile IP network system and connection switching method |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP11-207223 | 1999-07-22 | ||
JP20722399 | 1999-07-22 | ||
US09/624,072 US7009950B1 (en) | 1999-07-22 | 2000-07-24 | Mobile IP network system and connection switching method |
US11/332,180 US20060114856A1 (en) | 1999-07-22 | 2006-01-17 | Mobile IP network system and connection switching method |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/624,072 Continuation US7009950B1 (en) | 1999-07-22 | 2000-07-24 | Mobile IP network system and connection switching method |
Publications (1)
Publication Number | Publication Date |
---|---|
US20060114856A1 true US20060114856A1 (en) | 2006-06-01 |
Family
ID=16536291
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/624,072 Expired - Fee Related US7009950B1 (en) | 1999-07-22 | 2000-07-24 | Mobile IP network system and connection switching method |
US11/332,180 Abandoned US20060114856A1 (en) | 1999-07-22 | 2006-01-17 | Mobile IP network system and connection switching method |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/624,072 Expired - Fee Related US7009950B1 (en) | 1999-07-22 | 2000-07-24 | Mobile IP network system and connection switching method |
Country Status (4)
Country | Link |
---|---|
US (2) | US7009950B1 (en) |
EP (1) | EP1204250A4 (en) |
JP (1) | JP3895176B2 (en) |
WO (1) | WO2001008359A1 (en) |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20040047365A1 (en) * | 2000-10-07 | 2004-03-11 | Williams Philip J | Communications system enabling mobility and special services in an ip network |
US20050078618A1 (en) * | 2003-10-08 | 2005-04-14 | Moo-Yeon Woo | Hybrid base station transceiver |
US20050089008A1 (en) * | 2003-10-28 | 2005-04-28 | Curitel Communications, Inc. | Method for providing mobile packet data service in mobile communication system |
US20060146797A1 (en) * | 2004-12-30 | 2006-07-06 | Gerald Lebizay | Distributed voice network |
US20090080399A1 (en) * | 2002-02-20 | 2009-03-26 | Cisco Technology, Inc., A Corporation Of California | Methods and apparatus for supporting proxy mobile ip registration in a wireless local area network |
US20090238145A1 (en) * | 2001-02-21 | 2009-09-24 | Interdigital Technology Corporation | Method and apparatus for wireless communication with low-overhead mobility management |
US20100124204A1 (en) * | 2008-11-20 | 2010-05-20 | Samsung Electronics Co., Ltd. | Method and apparatus for improving unbalance of service of cell edge in wireless local area network |
US20110206008A1 (en) * | 2006-03-29 | 2011-08-25 | Pantech & Curitel Communications, Inc. | Packet switched radio telecommunication system supporting hard handover and method for hard handover |
US8325673B1 (en) * | 2007-10-02 | 2012-12-04 | At&T Intellectual Property I, L.P. | Personal multi-device nomadic media |
Families Citing this family (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2001008359A1 (en) * | 1999-07-22 | 2001-02-01 | Hitachi, Ltd. | Mobile ip network system and method of switching connection |
JP4652608B2 (en) * | 2001-05-16 | 2011-03-16 | Kddi株式会社 | Mobile IP data transfer method |
JP4404371B2 (en) * | 2001-06-08 | 2010-01-27 | 財団法人流通システム開発センタ− | Communication system using IP network |
US7339928B2 (en) | 2001-08-29 | 2008-03-04 | Alcatel Lucent | Micro-mobility network routing system and method |
KR100449574B1 (en) * | 2002-04-08 | 2004-09-22 | 주식회사 케이티프리텔 | Low-cost network system between a base station controller and a base transceiver station, and method for transmitting data between them |
US7289463B2 (en) | 2002-04-30 | 2007-10-30 | Alcatel Lucent | Hierarchical wireless network and an associated method for delivering IP packets to mobile stations |
MXPA05001200A (en) | 2002-08-01 | 2005-05-16 | Research In Motion Ltd | Always-on wireless internet protocol communication. |
US7480721B2 (en) | 2002-09-03 | 2009-01-20 | Interdigital Technology Corporation | Method and system for user initiated inter-device, inter-system, and inter-internet protocol address handoff |
US20040082330A1 (en) * | 2002-10-29 | 2004-04-29 | Marin James Scott | Method for handoff and redundancy using mobile IP |
JP4373475B2 (en) * | 2005-12-27 | 2009-11-25 | 株式会社日立コミュニケーションテクノロジー | Access gateway and flow control method in wireless system |
US20080123621A1 (en) * | 2006-11-29 | 2008-05-29 | Alexander Bachmutsky | High speed access broadcast system solution |
US8179859B2 (en) | 2008-02-21 | 2012-05-15 | Wang Ynjiun P | Roaming encoded information reading terminal |
US8989172B2 (en) * | 2008-07-22 | 2015-03-24 | Kyocera Corporation | Data routing through local network connected to a base station |
WO2010039907A1 (en) * | 2008-09-30 | 2010-04-08 | Spidercloud Wireless | Handoff procedures and intra-network data routing for femtocell networks |
US8191785B2 (en) | 2009-03-05 | 2012-06-05 | Hand Held Products, Inc. | Encoded information reading terminal operating in infrastructure mode and ad-hoc mode |
CN102076027B (en) * | 2009-11-19 | 2014-04-30 | 中兴通讯股份有限公司 | System, device and method for counting PPP negotiation states in wireless system |
CN103781149B (en) * | 2012-10-26 | 2017-04-26 | 华为技术有限公司 | BBusiness message forwarding processing method , system and access point AP |
Citations (25)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5471644A (en) * | 1993-07-29 | 1995-11-28 | Motorola, Inc. | Method of reducing audio gap in downlink during handoff of cellular radiotelphone |
US5682416A (en) * | 1995-05-09 | 1997-10-28 | Motorola, Inc. | Method and apparatus communication handover in a communication system |
US5708655A (en) * | 1996-06-14 | 1998-01-13 | Telefonaktiebolaget L M Ericsson Publ | Method and apparatus for addressing a wireless communication station with a dynamically-assigned address |
US5862345A (en) * | 1996-02-07 | 1999-01-19 | Nec Corporation | System for location multicasting and database management for mobile sessions in any computer subnetworks without using a home router of a home subnetwork |
US5889770A (en) * | 1994-04-08 | 1999-03-30 | Nokia Telecommunicaitons Oy | Location updating for a packet-switched data service in a mobile communciation system |
US5949773A (en) * | 1998-03-31 | 1999-09-07 | Motorola, Inc. | Method for transferring a data signal in a wireless communications system |
US5953668A (en) * | 1996-12-17 | 1999-09-14 | Airnet Communications Corporation | Radio channel management functionality distribution in wireless communication system |
US5958018A (en) * | 1996-10-30 | 1999-09-28 | Lucent Technologies Inc. | Wireless services data network translating mac address to asynchronous transfer mode (ATM) address |
US6023461A (en) * | 1997-10-10 | 2000-02-08 | Nec Usa, Inc. | Handoff method for an ATM wireless network wherein both the switch and the mobile buffer cells and the mobile controls when the handoff will occur |
US6078575A (en) * | 1996-10-01 | 2000-06-20 | Lucent Technologies Inc. | Mobile location management in ATM networks |
US6215779B1 (en) * | 1998-09-22 | 2001-04-10 | Qualcomm Inc. | Distributed infrastructure for wireless data communications |
US6233458B1 (en) * | 1997-06-24 | 2001-05-15 | Nokia Telecommunications Oy | Re-routing procedure |
US6240089B1 (en) * | 1997-02-24 | 2001-05-29 | Nec Corporation | Method of multicasting for mobile host used in any one of subnetworks connected to one another |
US6272129B1 (en) * | 1999-01-19 | 2001-08-07 | 3Com Corporation | Dynamic allocation of wireless mobile nodes over an internet protocol (IP) network |
US6366561B1 (en) * | 1999-11-03 | 2002-04-02 | Qualcomm Inc. | Method and apparatus for providing mobility within a network |
US6385451B1 (en) * | 1998-09-14 | 2002-05-07 | Nokia Mobile Phones Limited | Handover between mobile communication networks |
US6404754B1 (en) * | 1998-09-07 | 2002-06-11 | Lg Information & Communications, Ltd. | Radio packet data terminal and method of determining internet interworking protocol address |
US6487406B1 (en) * | 1999-06-16 | 2002-11-26 | Telcordia Technologies, Inc. | PCS-to-mobile IP internetworking |
US20030039237A1 (en) * | 1997-09-25 | 2003-02-27 | Jan E Forslow | Common access between a mobile communications network and an external network with selectable packet-switched and circuit-switched services |
US6535493B1 (en) * | 1998-01-15 | 2003-03-18 | Symbol Technologies, Inc. | Mobile internet communication protocol |
US6587882B1 (en) * | 1997-08-01 | 2003-07-01 | Kabushiki Kaisha Toshiba | Mobile IP communication scheme using visited site or nearby network as temporal home network |
US6654359B1 (en) * | 1998-12-11 | 2003-11-25 | Lucent Technologies Inc. | Wireless access to packet-based networks |
US6661782B1 (en) * | 1997-01-20 | 2003-12-09 | Nokia Telecommunications Oy | Routing area updating in packet radio network |
US6724739B1 (en) * | 1999-02-25 | 2004-04-20 | Qualcomm, Incorporated | Method for handoff between an asynchronous CDMA base station and a synchronous CDMA base station |
US7009950B1 (en) * | 1999-07-22 | 2006-03-07 | Hitachi, Ltd. | Mobile IP network system and connection switching method |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3609624B2 (en) * | 1997-08-01 | 2005-01-12 | 株式会社東芝 | Mobile computer device, mobile computer management device, mobile information management device, and communication control method |
JP3080039B2 (en) * | 1997-08-29 | 2000-08-21 | 三菱電機株式会社 | Location registration method of mobile terminal in mobile communication system |
JPH11252182A (en) * | 1998-03-05 | 1999-09-17 | Fujitsu Ltd | Terminal containing method and node device with terminal containing function |
US7675138B2 (en) * | 2005-09-30 | 2010-03-09 | Broadcom Corporation | On-chip capacitor structure |
-
2000
- 2000-07-18 WO PCT/JP2000/004817 patent/WO2001008359A1/en active Application Filing
- 2000-07-18 JP JP2001512749A patent/JP3895176B2/en not_active Expired - Fee Related
- 2000-07-18 EP EP00946384A patent/EP1204250A4/en not_active Withdrawn
- 2000-07-24 US US09/624,072 patent/US7009950B1/en not_active Expired - Fee Related
-
2006
- 2006-01-17 US US11/332,180 patent/US20060114856A1/en not_active Abandoned
Patent Citations (25)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5471644A (en) * | 1993-07-29 | 1995-11-28 | Motorola, Inc. | Method of reducing audio gap in downlink during handoff of cellular radiotelphone |
US5889770A (en) * | 1994-04-08 | 1999-03-30 | Nokia Telecommunicaitons Oy | Location updating for a packet-switched data service in a mobile communciation system |
US5682416A (en) * | 1995-05-09 | 1997-10-28 | Motorola, Inc. | Method and apparatus communication handover in a communication system |
US5862345A (en) * | 1996-02-07 | 1999-01-19 | Nec Corporation | System for location multicasting and database management for mobile sessions in any computer subnetworks without using a home router of a home subnetwork |
US5708655A (en) * | 1996-06-14 | 1998-01-13 | Telefonaktiebolaget L M Ericsson Publ | Method and apparatus for addressing a wireless communication station with a dynamically-assigned address |
US6078575A (en) * | 1996-10-01 | 2000-06-20 | Lucent Technologies Inc. | Mobile location management in ATM networks |
US5958018A (en) * | 1996-10-30 | 1999-09-28 | Lucent Technologies Inc. | Wireless services data network translating mac address to asynchronous transfer mode (ATM) address |
US5953668A (en) * | 1996-12-17 | 1999-09-14 | Airnet Communications Corporation | Radio channel management functionality distribution in wireless communication system |
US6661782B1 (en) * | 1997-01-20 | 2003-12-09 | Nokia Telecommunications Oy | Routing area updating in packet radio network |
US6240089B1 (en) * | 1997-02-24 | 2001-05-29 | Nec Corporation | Method of multicasting for mobile host used in any one of subnetworks connected to one another |
US6233458B1 (en) * | 1997-06-24 | 2001-05-15 | Nokia Telecommunications Oy | Re-routing procedure |
US6587882B1 (en) * | 1997-08-01 | 2003-07-01 | Kabushiki Kaisha Toshiba | Mobile IP communication scheme using visited site or nearby network as temporal home network |
US20030039237A1 (en) * | 1997-09-25 | 2003-02-27 | Jan E Forslow | Common access between a mobile communications network and an external network with selectable packet-switched and circuit-switched services |
US6023461A (en) * | 1997-10-10 | 2000-02-08 | Nec Usa, Inc. | Handoff method for an ATM wireless network wherein both the switch and the mobile buffer cells and the mobile controls when the handoff will occur |
US6535493B1 (en) * | 1998-01-15 | 2003-03-18 | Symbol Technologies, Inc. | Mobile internet communication protocol |
US5949773A (en) * | 1998-03-31 | 1999-09-07 | Motorola, Inc. | Method for transferring a data signal in a wireless communications system |
US6404754B1 (en) * | 1998-09-07 | 2002-06-11 | Lg Information & Communications, Ltd. | Radio packet data terminal and method of determining internet interworking protocol address |
US6385451B1 (en) * | 1998-09-14 | 2002-05-07 | Nokia Mobile Phones Limited | Handover between mobile communication networks |
US6215779B1 (en) * | 1998-09-22 | 2001-04-10 | Qualcomm Inc. | Distributed infrastructure for wireless data communications |
US6654359B1 (en) * | 1998-12-11 | 2003-11-25 | Lucent Technologies Inc. | Wireless access to packet-based networks |
US6272129B1 (en) * | 1999-01-19 | 2001-08-07 | 3Com Corporation | Dynamic allocation of wireless mobile nodes over an internet protocol (IP) network |
US6724739B1 (en) * | 1999-02-25 | 2004-04-20 | Qualcomm, Incorporated | Method for handoff between an asynchronous CDMA base station and a synchronous CDMA base station |
US6487406B1 (en) * | 1999-06-16 | 2002-11-26 | Telcordia Technologies, Inc. | PCS-to-mobile IP internetworking |
US7009950B1 (en) * | 1999-07-22 | 2006-03-07 | Hitachi, Ltd. | Mobile IP network system and connection switching method |
US6366561B1 (en) * | 1999-11-03 | 2002-04-02 | Qualcomm Inc. | Method and apparatus for providing mobility within a network |
Cited By (21)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20040047365A1 (en) * | 2000-10-07 | 2004-03-11 | Williams Philip J | Communications system enabling mobility and special services in an ip network |
US20090238145A1 (en) * | 2001-02-21 | 2009-09-24 | Interdigital Technology Corporation | Method and apparatus for wireless communication with low-overhead mobility management |
US8792323B2 (en) * | 2001-02-21 | 2014-07-29 | Interdigital Technology Corporation | Method and apparatus for wireless communication with low-overhead mobility management |
US20130142167A1 (en) * | 2001-02-21 | 2013-06-06 | Interdigital Technology Corporation | Method and apparatus for wireless communication with low-overhead mobility management |
US8213385B2 (en) * | 2001-02-21 | 2012-07-03 | Interdigital Technology Corporation | Method and apparatus for wireless communication with low-overhead mobility management |
US8422467B2 (en) * | 2002-02-20 | 2013-04-16 | Cisco Technology, Inc. | Methods and apparatus for supporting proxy mobile IP registration in a wireless local area network |
US20090080399A1 (en) * | 2002-02-20 | 2009-03-26 | Cisco Technology, Inc., A Corporation Of California | Methods and apparatus for supporting proxy mobile ip registration in a wireless local area network |
US7366180B2 (en) * | 2003-10-08 | 2008-04-29 | Samsung Electronics Co., Ltd. | Hybrid base station transceiver for plural networks |
US20050078618A1 (en) * | 2003-10-08 | 2005-04-14 | Moo-Yeon Woo | Hybrid base station transceiver |
US20050089008A1 (en) * | 2003-10-28 | 2005-04-28 | Curitel Communications, Inc. | Method for providing mobile packet data service in mobile communication system |
US20060146797A1 (en) * | 2004-12-30 | 2006-07-06 | Gerald Lebizay | Distributed voice network |
US8204044B2 (en) | 2004-12-30 | 2012-06-19 | Intel Corporation | Method and network element for voice-over-IP (VoIP) communications in a mobile IP network |
US7593390B2 (en) * | 2004-12-30 | 2009-09-22 | Intel Corporation | Distributed voice network |
US8605714B2 (en) | 2004-12-30 | 2013-12-10 | Intel Corporation | Method and network element for establishing a IP communications session between mobile communication devices |
US20100008345A1 (en) * | 2004-12-30 | 2010-01-14 | Gerald Lebizay | Distributed voice network |
US20110206008A1 (en) * | 2006-03-29 | 2011-08-25 | Pantech & Curitel Communications, Inc. | Packet switched radio telecommunication system supporting hard handover and method for hard handover |
US8249023B2 (en) * | 2006-03-29 | 2012-08-21 | Pantech Co., Ltd. | Packet switched radio telecommunication system supporting hard handover and method for hard handover |
US8325673B1 (en) * | 2007-10-02 | 2012-12-04 | At&T Intellectual Property I, L.P. | Personal multi-device nomadic media |
US9118959B2 (en) | 2007-10-02 | 2015-08-25 | At&T Intellectual Property I, L.P. | Personal multi-device nomadic media |
US20100124204A1 (en) * | 2008-11-20 | 2010-05-20 | Samsung Electronics Co., Ltd. | Method and apparatus for improving unbalance of service of cell edge in wireless local area network |
US8576802B2 (en) * | 2008-11-20 | 2013-11-05 | Samsung Electronics Co., Ltd | Method and apparatus for improving unbalance of service of cell edge in wireless local area network |
Also Published As
Publication number | Publication date |
---|---|
EP1204250A1 (en) | 2002-05-08 |
EP1204250A4 (en) | 2009-04-01 |
WO2001008359A1 (en) | 2001-02-01 |
US7009950B1 (en) | 2006-03-07 |
JP3895176B2 (en) | 2007-03-22 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US20060114856A1 (en) | Mobile IP network system and connection switching method | |
AU2005285179B2 (en) | Wireless communication methods and components that implement handoff in wireless local area networks | |
US7372835B2 (en) | Handoff system and method of dual mode mobile for connecting mobile communication system and wireless network | |
CA2580180C (en) | Wireless communication methods and components for facilitating multiple network type compatibility | |
US7738425B2 (en) | Method of initializing and establishing links in a multi-mode mobile terminal | |
US7035636B1 (en) | System and method for controlling packet data service in mobile communication network | |
US20020064144A1 (en) | SGSN semi anchoring durjing the inter SGSN SRNC relocation procedure | |
US20060159047A1 (en) | Method and system for context transfer across heterogeneous networks | |
US20110044290A1 (en) | Communication terminal apparatus and handover method | |
US7983676B2 (en) | Inter-system handover | |
EP1878288A2 (en) | A method of supporting handover in a multi-mode mobile station | |
WO2005081428A1 (en) | Mobile communication system and mobile communication method | |
KR20010001928A (en) | Method for operating handover in packet mobile communication network | |
US20070280176A1 (en) | Method and apparatus for facilitating a fast handoff in a wireless metropolitan area network | |
US6094424A (en) | Mobile host roaming ATM virtual circuit rerouting method and apparatus | |
US20090180437A1 (en) | Communication apparatus and handover method | |
CA2645999C (en) | Handoff of an access terminal at the network layer in an access network | |
KR20000046518A (en) | Hand-off processing method in atm switching system |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |